Deep under the ice, Antarctica’s mountain ranges have long remained a mystery. All of that is beginning to change, however, thanks to an international team of scientists led by the British Antarctic Survey.
The map, called Bedmap2, adds 25 million measurements to its predecesser released in 2001. The information used was taken over the past 20 years from the ground, air, including seven years of surface elevation readings from NASA’s IceSat satellite and laser and ice-penetrating radar data from NASA’s Operation IceBridge.
In comparing the two maps, Peter Fretwell of the British Antarctic Survey said in a statement that while the first gave scientists an idea to work with, the newest one is much more true to life.
“Before we had a regional overview of the topography, but this new map, with its much higher resolution, shows the landscape itself; a complex landscape of mountains, hills and rolling plains, dissected by valleys troughs and deep gorges," he said.
As a result, scientists have a much clearer vision of what lies beneath, which in turn has meant a few surprises.
For example, the researchers discovered that the volume of ice located in Antarctica is 4.6 percent greater than previously thought.
Furthermore, the scientists found that the mean bed depth of the continent is 95 meters, 60 meters lower than estimated. Also the volume of ice that is grounded with a bed below sea level is 23 percent greater than originally thought, meaning there is a large volume of ice that is susceptible to rapid melting.
Finally, the deepest point, located under the famous Byrd Glacier, is around 400 meters deeper than the previously identified deepest point.
Given this new information, the researchers estimate that the potential contribution to global sea level rise from Antarctica is 58 meters.
In the end, however, Bedmap2 represents much more than a map of the landscape for the scientists.
“The data we’ve put together on the height and thickness of the ice and the shape of the landscape below are fundamental to modeling the behavior of the ice sheet in the future,” said Hamish Pritchard, a co-lead author on the study.
And that matters, Pritchard explains, “because in some places, ice along the edges of Antarctica is being lost rapidly to the sea, driving up sea level.”